1. Home
  2. wmdr
  3. ObservingMethodTerrestrial
  4. _381

Entry: image velocimetry

stable

URI: http://codes.wmo.int/wmdr/ObservingMethodTerrestrial/381    

The measurement of velocities at the free surface of a moving water body using PIV (Particle Image Velocimetry) or LSPIV (Large Scale Particle Image Velocimetry) operates on the principle of statistical estimation of the displacement of groups of particles in consecutive images. The estimation is most-often made using cross-correlations applied to the spatial distribution of the light intensity defining the patterns (i.e., the pattern image) enclosed in small interrogation areas covering the whole image. The results of image processing is a velocity vector field centered on the interrogation area grid determined by dividing the estimated displacement with the time between images in the pair. Note: Given that LSPIV images cover large areas usually recorded from an oblique angle to the flow surface, an additional step is customarily involved, i.e. image orthorectification [Based on Aberle et al., Experimental Hydraulics: Instrumentation and Measurement Techniques, 2017 and Muste et al., Large-Scale Particle Image Velocimetry for Measurements in Riverine Environments, Special Issue on Hydrologic Measurements, Water Resources Research 44, 2008].

Core metadata

is a Concept
submitted byamilan17

Download formats available

RDF ttl plain with metadata
RDF/XML plain with metadata
JSON-LD plain with metadata
CSV plain with metadata
Export all export

All metadata properties

date submitted 2 Jan 2024 17:12:41.519
definition
entity image velocimetry
source graph graph

description The measurement of velocities at the free surface of a moving water body using PIV (Particle Image Velocimetry) or LSPIV (Large Scale Particle Image Velocimetry) operates on the principle of statistical estimation of the displacement of groups of particles in consecutive images. The estimation is most-often made using cross-correlations applied to the spatial distribution of the light intensity defining the patterns (i.e., the pattern image) enclosed in small interrogation areas covering the whole image. The results of image processing is a velocity vector field centered on the interrogation area grid determined by dividing the estimated displacement with the time between images in the pair. Note: Given that LSPIV images cover large areas usually recorded from an oblique angle to the flow surface, an additional step is customarily involved, i.e. image orthorectification [Based on Aberle et al., Experimental Hydraulics: Instrumentation and Measurement Techniques, 2017 and Muste et al...
item class Concept
label image velocimetry
notation 381
register observing method terrestrial
status status stable
submitter
account name https://api.github.com/users/amilan17
name amilan17

type register item
version info 1
Pane is loading...
Select tab to expand

Definition

description The measurement of velocities at the free surface of a moving water body using PIV (Particle Image Velocimetry) or LSPIV (Large Scale Particle Image Velocimetry) operates on the principle of statistical estimation of the displacement of groups of particles in consecutive images. The estimation is most-often made using cross-correlations applied to the spatial distribution of the light intensity defining the patterns (i.e., the pattern image) enclosed in small interrogation areas covering the whole image. The results of image processing is a velocity vector field centered on the interrogation area grid determined by dividing the estimated displacement with the time between images in the pair. Note: Given that LSPIV images cover large areas usually recorded from an oblique angle to the flow surface, an additional step is customarily involved, i.e. image orthorectification [Based on Aberle et al., Experimental Hydraulics: Instrumentation and Measurement Techniques, 2017 and Muste et al...
label image velocimetry
notation 381
type Concept